学步园

   public void WriteContext(string Context,string path) 
        {
            StreamWriter sw = new StreamWriter(path);
            sw.Write(Context);
            sw.Close();
            sw.Dispose();
        }

        private string ReadContext(string path)
        {
            FileStream fs = new FileStream(path, FileMode.Open);
            StreamReader sr = new StreamReader(fs);
            string context = sr.ReadToEnd();
            fs.Close();
            sr.Close();
            sr.Dispose();
            fs.Dispose();
            return context;
        }

或：

//读取文本　
StreamReader sr = new StreamReader(文本文件的路径);
string str = sr.ReadToEnd();
sr.Close();
//替换文本
str = str.Replace("E103","E103**");
//更改保存文本
StreamWriter sw = new StreamWriter(文本文件的路径,false);
sw.WriteLine(str);
sw.Close();